Satellite sandwich technique improves analysis of geographical data

University of Cincinnati News: For the sandwich, you want rich and sweet flavors, blended into a smooth, creamy texture – and you want it all in one convenient package. That’s similar to how you want the satellite data, and Bo Yang, a University of Cincinnati graduate student in geography, has a formula for crafting a deeply informative and easily utilized satellite sandwich.

He’ll present his research, “Spatiotemporal Cokriging [sic] Images Fusion of Multi-Sensor Land Surface Temperature over Thaw Lakes on North Alaska,” at the Association of American Geographers annual meeting to be held April 9-13 in Los Angeles. The interdisciplinary forum is attended by more than 7,000 scientists from around the world and features an array of geography-related presentations, workshops and field trips.

For his master’s thesis, Yang studied thermal data from two different types of polar-orbiting satellite systems. One system frequently records large images of a region on Earth but in little detail. Another system records small images less frequently but in much greater detail. Analyzing two massive sets of parallel data and finding a way to make them overlap can be complicated and time-consuming. Yang is developing a method to simplify the process.

“In an easy-to-understand way, I am trying to derive both very high-definition and high-frequency revisiting imagery from two satellite-carried sensors,” Yang says. “I use the spatial statistics technique known as co-kriging to fuse multi-sensor land surface temperature images.”

Yang uses an algorithm he devised to fill the spatiotemporal gaps between the two data sets. The result is an intricately detailed map covering a large surface area that allows geographers to quickly derive daily – even hourly – surface temperature and emissivity information. These environmental parameters are important to agriculture and water resource management and can be used to detect the onset and severity of drought.

Yang used thaw lakes in the Arctic Coastal Plain of Alaska as his study area. These lakes are a critical component to Arctic ecology and one that is considered vulnerable to the effects of climate warming. Yang’s work is connected to a larger project under way in the region, the Circumarctic Lakes Observation Network...

NASA image of central Alaska

Getting a better look at Sandy's wake of destruction

Newswise via Drexel University: Images of the destruction caused by Hurricane Sandy have captured the immense power of what many experts have termed a “superstorm.” These snapshots and videos might not tell the whole story, however. A group of Drexel University engineers are now trying to give rescue and recovery workers a better picture of the storm’s damages that can’t be seen by the naked eye.

Using a combination of images from satellites and remote controlled aircrafts and cameras equipped with infrared and ultraviolet technology, the researchers are hoping to paint a detailed picture of Sandy’s path of destruction that could help emergency workers respond to the next natural disaster.

“During Hurricane Sandy, 7.5 million power outages were reported and thousands of people were still without power weeks after the hurricane,” said Dr. Anu Pradhan an assistant professor in Drexel’s College of Engineering and the lead researcher on the National Science Foundation-funded research team. “This is due to the massive destruction, it’s difficult to see the full scope of it by walking through the sites, we need a broader picture that shows the various layers of damage both seen and unseen.”

Infrared (IR) and ultraviolet (UV) imaging technology, combined with acoustic emission (AE) testing can reveal damages to power lines, trees, telephone poles and buildings that appeared to be unscathed.

“Infrared and ultraviolet cameras can capture radiation that is not visible to the naked eye,” said Dr. Ivan Bartoli, an assistant professor in the College of Engineering and a co-researcher for the project. “Different anomalies in power lines can be observed using IR/UV imaging, in the future, using a combination of high resolution satellite images and close-range aerial photography with IR/UV filters, we could determine which power lines are working and which are damaged.”

Acoustic emission testing uses sound waves to test the elasticity of trees and telephone poles and can determine whether or not they’ve been damaged internally to the point where they could be a falling hazard.

...“In addition to the lives lost and destruction caused by Hurricane Sandy, the residual effects are still very much with us,” said co-researcher Dr. Antonios Kontsos, an assistant professor in the College of Engineering. “Our goal is to make sure that responders have even more information at their disposal the next time something like this happens so that perhaps some of this loss can be prevented.”...

In New Jersey, along Hurricane Sandy's path of destruction, Drexel engineers are using infrared and ultraviolet imaging technology and acoustic emission testing combined with low-altitude aircraft photography to generate detailed maps for recovery workers to triage their efforts.  Image from Drexel University

Old aerial photos supply new knowledge on glaciers in Greenland

Kurt H. Kjaer in Environmental Research Web: The glaciers in southeast Greenland are retreating rapidly with the ongoing global climate change. But now research from the University of Copenhagen shows that the glaciers can recuperate within a short timeframe if temperatures are to drop. The results are based on a collection of Danish aerial photos combined with both old and modern satellite imagery as well as field work. The scientific results have created international attention and have been published as a cover story in the highly esteemed journal Nature Geoscience.

"We have managed to get an overview of the glacial evolution over a period of 80 years. This is the first time ever this has been done in a study of glaciers in Greenland. Results show that glaciers can recuperate within a short time frame if climate changes and temperatures drop, as it has in a period after the 1940s," says PhD student and lead-author on the project Anders Bjørk, from Professor Eske Willerslev's Centre for GeoGenetics from University of Copenhagen.

Anders Bjørk adds: "Most of the scientific foundation, models, and theories on glaciers in Greenland and how global warming affects them are based on observations from satellites over the last ten years. Otherwise scientists have had to use previous warming events way into the past when wanting to compare today's massive retreat."

...Originally the many aerial photos, which have been achieved Danish National Survey and Cadastre, were used for producing new maps of the region in the early 1930s, as Denmark and Norway were fighting over the right of disposal of East Greenland, a fight without casualties which Denmark won at the International Court in Haag in the Netherlands in 1933....

Plate from a publication of the first IPY (International Polar Year, 1882-1883).  This photo by Adolphus Greely, Carlheim-Gyllenskiöld is older than the trove in question, but it was the best I could find in the public domain

Unparalleled views of earth's coast with HREP-HICO

NASA: Scanning the globe from the vantage point of the International Space Station is about more than the fantastic view. While cruising in low Earth orbit, the space station HICO and RAIDS Experiment Payload–Hyperspectral Imager for the Coastal Ocean, or HREP-HICO, gives researchers a valuable new way to view the coastal zone.

Using an imaging spectrometer mounted outside the station on the Japanese Exposed Facility of the Kibo Laboratory, researchers are collecting data about the Earth that will help them to better understand coastal environments and other regions around the world.

Why is this important? Coastal waters are an important link between local and global economic development and environmental sustainability. Coastal zones support many of the world's major cities (and their industrial zones, ports, recreational facilities); they also include critical ecosystems that support fisheries and protect shorelines.

HREP-HICO is a visible to near-infrared wavelength spectrometer optimized for environmental characterization of coastal zones and mapping of terrestrial geophysical features of the Earth. Mike Corson, Ph.D., principal investigator for HREP-HICO at the Naval Research Laboratory in Washington, D.C., explained that "Coastal environmental characterization includes producing maps of near-shore bathymetry, water clarity, organic and inorganic dissolved and suspended matter and bottom characteristics…. Such maps are important to Navy and Marine Corps who operate in coastal areas."

...Taking images of the ocean, however, is harder than it seems. As the first space-borne imaging spectrometer designed to sample the coastal ocean, HREP-HICO has to account for the vast breadth of global coastlines, the complex makeup of the ocean, changing weather conditions, and the location of the sun. These challenges can easily obscure views of the water and the sea floor -- yielding poor and incomprehensible imagery...

Image from NASA

Imaging the earth

Space Mart: From monitoring vanishing glaciers to the accounting of forestry, hydropower and mining assets as steps to boost sustainable development here on Earth, the power of satellite remote sensing plays an increasingly vital role. These topics and others are highlighted in the Fall 2010 issue of the quarterly print and online publication - Imaging Notes magazine.

"Secure World Foundation in 2009 established a partnership with Imaging Notes magazine," said Dr. Ray Williamson, SWF's Executive Director. "A key focus of our organization centers on strengthening or developing the policies and institutions that improve the utility of space technologies in support of human and environmental security needs. We are pleased to be a partner with Imaging Notes to help support our objectives."

The just-issued publication includes articles centered on security and intelligence, sustainable development using Earth observations and the continuing growth of Community Remote Sensing, or CRS for short.

Imaging Notes and Secure World Foundation have taken a lead role in gauging the expanding use of CRS - a new field that combines remote sensing with citizen science, social networks, and crowd-sourcing to enhance the data obtained from traditional sources. It includes the collection, calibration, analysis, communication, or application of remotely sensed information by these community means. Other Imaging Notes articles delve into satellite camera systems that feed imagery to such users as Google Earth and the Weather Channel and information sharing incongruities in the intelligence community….

Satellite image of Bahia Engaño, Chubut, Argentina

The role of satellite imagery in climate change research, or ICESCAPE

Dr. Kevin Arrigo in Armed with Science, which seems to be a tentacle of the US Department of Defense. Arrigo is a Professor in the Department of Environmental Earth System Science at Stanford and the Chief Scientist for NASA’s ICESCAPE (Impact of Climate change on the Eco-Systems and Chemistry of the Arctic Pacific Environment) mission this summer onboard US Coast Guard Cutter HEALY: …Satellite remote sensing plays two important roles within ICESCAPE. First, by analyzing daily satellite images of everything from sea ice cover to ocean temperature to the concentration of chlorophyll in the water, we can conduct a more efficient sampling program. Want to sample heavy pack ice? Or avoid it? Satellites tell us where to go. Want to collect seawater samples with lots of phytoplankton? Satellites tell us where they are.

The second role played by satellite imagery is a bit different –- it is used to “fill in the blanks” in our field program. Even though ICESCAPE will sample a big chunk of the Chukchi and Beaufort seas, we can’t be everywhere all the time. That would take lots of ships, lots of time, and lots of money. But satellites can tell us what conditions were like before we arrive, after we leave, and in areas we don’t sample. The result? A better understanding of what we are seeing while we are here.

But this is a two-way street. We can help satellite data, too. Robert Frouin (Scripps Institution of Oceanography) is working on ways to extract more information from satellite images when sea ice or high clouds are around. Formerly, satellite pixels (like those tiny dots that make up a picture in your newspaper) that were “contaminated” by clouds or sea ice were discarded or ignored. Not anymore. Frouin’s approach works kind of like those TV shows where the star pushes a button and magically makes a fuzzy picture look sharper. And in a region as cloudy and ice covered as the Arctic, every scrap of information helps!

Finally, field data collected during ICESCAPE by Greg Mitchell (Scripps Institution of Oceanography), Stan Hooker (NASA Goddard Space Flight Center) and Kevin Arrigo (Stanford University) will be used to ensure that satellite data, and the products that are derived from them, are as accurate as they can be (but more about this in later posts)….

This image of Alaska and its ocean environs from June 24, 2010 combines data from different satellites. Brown is land; gray is Arctic sea ice; and the colored areas represent different levels of chlorophyll. Chlorophyll a, the green pigment that aids photosynthesis, is an indicator of the amount of phytoplankton in the ocean. On this image, red illustrates areas of high chlorophyll concentration, where there is a lot of phytoplankton and hence a lot of primary productivity. (Image: Gert van Dijken, Science and Engineering Associate at Stanford University)

In series of flyovers, a scientific snapshot of New York City

Mireya Navarro in the New York Times: While most residents were sleeping, a twin-engine Shrike Commander flew serial missions over the city recently, cruising low like Superman and back and forth like a lawn mower. Equipped with a laser system, the plane collected highly precise images of the city, its rooftops, trees, wetlands and much of what lies in between.

The early morning flyovers are expected to yield the most detailed three-dimensional picture of New York City to date, with an emphasis on structures, elevations, sun and shade, and nooks and crannies relevant to the city’s emergency response system and its environmental goals.

The data will be used, among other things, to create up-to-date maps of the areas most prone to flooding, the buildings best suited for the installation of solar power and the neighborhoods most in need of trees. An advisory panel of experts formed by the mayor has warned that the city must prepare for more rain and an increased risk of coastal flooding in the coming decades as a result of global climate change.

Rohit T. Aggarwala, the director of the city’s Office of Long-Term Planning and Sustainability, said the effort would result in a picture of New York’s physical space “in far more detail than what we had before.” The effort, which will cost about $450,000, is part of Mayor Michael R. Bloomberg’s broader environmental agenda, known as PlaNYC….

An aerial view of Manhattan in 1919

Cameras to settle Himalayan glacier dispute

Smriti Mallapaty in SciDev.net: Cameras being installed high in the Nepal Himalayas will help settle the issue of whether and how fast glaciers in the high mountain region are retreating — or advancing. In April, the Nepal government gave the green signal for the extreme ice survey (EIS) that uses time-lapse imagery (a photographic technique in which slow action appears to be greatly speeded up), conventional photography and video to document the changing nature of glacial ice and visually communicate the changes to local communities.

The EIS project hopes to provide credible evidence that Himalayan glaciers are receding due to global warming. Projections by the United Nations Inter-Governmental Panel on Climate Change (IPCC) in its 2007 report that Himalayan glaciers could disappear by the year 2035 were later challenged as lacking scientific basis (see Glacier dispute reveals holes in research).

"Once the footage is released, no one will be able to dispute it [receding glaciers], because the image of receding glaciers will be right before their eyes,'' Prashant Singh, director of development and marketing at the World Wildlife Fund in Nepal, told SciDev.Net.

To fully understand glacial dynamics, the project will incorporate historical images, satellite imagery and time-lapse photography. All data will be open source, used to develop models, predictions and policies. This is the first time that such a survey is being conducted in the Himalayas. Similar surveys have been conducted in Greenland, Iceland and Alaska.

Under the project cameras will be set up in three locations around the Khumbu glacier of Mount Everest and two near a hanging glacier on Ama Dablam (hanging glaciers originate on the wall of a glacier valley and descend only part of the way to the surface of the main glacier). Each camera will shoot at 30-minute intervals during daylight, accumulating over 8,000 images every year for a period of two years. The stills will eventually be stitched into a stunning 60-second time-lapse clip….

Khumbu icefall, shot by Uwe Gille on 26 Apr 2005 (UTC), Wikimedia Commons, under the Creative Commons Attribution ShareAlike 3.0 License

Collapse of the ice bridge supporting Wilkins Ice Shelf appears imminent

European Space Agency: The Wilkins Ice Shelf is at risk of partly breaking away from the Antarctic Peninsula as the ice bridge that connects it to Charcot and Latady Islands looks set to collapse. The beginning of what appears to be the demise of the ice bridge began this week when new rifts forming along its centre axis resulted in a large block of ice breaking away.

The Advanced Synthetic Aperture Radar (ASAR) images acquired on 2 April by ESA’s Envisat satellite confirm that the rifts are quickly expanding along the ice bridge.
Dr Angelika Humbert from the Institute of Geophysics, Münster University, and Dr Matthias Braun from the Center for Remote Sensing, University of Bonn, witnessed the recent development during their daily monitoring activities of the ice sheet using data from Envisat and the German Aerospace Center’s TerraSAR-X satellite.

By having a time series of radar satellite images throughout this event, Humbert and Braun are able to determine how the rifts develop and how the narrowest part of the bridge responds to these changes. Knowing these details allows them to learn more about the behaviour of ice under stress.

Satellite acquisitions of the ice shelf are available to the public via ESA’s ‘Webcam from Space’. The web page will be updated with Envisat images as they are received to allow the public to witness the event…..

Envisat’s Advanced Synthetic Aperture Radar (ASAR) captured the early stage of the disruption of the ice bridge that connects the Wilkins Ice Shelf to Charcot and Latady Islands on 2 April 2009 at 05:18 UTC. The new rifts that developed along the length axis of the ice bridge are visible. The first detachment along these new rifts occurred about seven hours later.  Credits: ESA (Annotations by A. Humbert, Münster University)

New 'pollution radar' developed to provide unprecedented picture of urban smog

EurekAlert: Scientists and industrialists have invented a sophisticated new air quality measuring device that can act as a pollution radar over cities. A team from the Surrey Satellite Technology Ltd, the University of Leicester and EADS Astrium are behind the technology that can be placed on satellites to provide unprecedented detail of gases in the atmosphere.

The researchers are also developing ground-based instruments this year, which will be able to create 3D maps of atmospheric gases.

The technologies have emerged from the UK's Centre for Earth Observation Instrumentation (CEOI) which is actively engaged in the development of novel Earth observation instrumentation and acts as a catalyst for the development of technologies for environmental monitoring from space. It is jointly supported via the Natural Environment Research Council (NERC) and Department of Innovation, Universities and Skills (DIUS).

Professor Paul Monks from the University of Leicester is one of the project leaders of the Compact Air Quality Spectrometer (CompAQS), a CEOI project to develop a compact imaging spectrometer operating in the ultra violet and visible (UV/VIS) part of the spectrum, with a number of potential applications on satellite platforms. The technology developed is now being adapted, through the NERC knowledge exchange funding into the CityScan project, to enable the quality of the air to be easily and continuously monitored across physically large urban and industrial spaces.

He said: "The instrument has been developed for potential deployment as a small satellite payload and provides the performance of current, comparable instruments, which are significantly larger in size. Its compact size, achieved through the use of a novel optical design, means that the costs of manufacture, platform development and launch can be minimized….

The Centre for Earth Observation Instrumentation's Compact Air Quality Spectrometer, a project which involved Professor Paul Monks of the University of Leicester. Image from the University's website.